The tui function itself had a few sub-functions and therefore basically already was class-like. Making it an actual one with proper methods improved readability.
The curses wrapper was dropped in favour of __entry/exit__ methods that implement the same behaviour. Kudos to Paolo Bonzini for proposing it and supplying me with most of the code. Also renamed single character variable name, so the name reflects the content. Signed-off-by: Janosch Frank <fran...@linux.vnet.ibm.com> --- scripts/kvm/kvm_stat | 121 ++++++++++++++++++++++++++++++++------------------- 1 file changed, 77 insertions(+), 44 deletions(-) diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat index 8efe3b8..eee3290 100755 --- a/scripts/kvm/kvm_stat +++ b/scripts/kvm/kvm_stat @@ -539,63 +539,95 @@ class Stats(object): LABEL_WIDTH = 40 NUMBER_WIDTH = 10 -def tui(screen, stats): - curses.use_default_colors() - curses.noecho() - drilldown = False - fields_filter = stats.fields_filter - def update_drilldown(): - if not fields_filter: - if drilldown: - stats.fields_filter = None +class Tui(object): + def __init__(self, stats): + self.stats = stats + self.screen = None + self.drilldown = False + self.fields_filter = self.stats.fields_filter + self.update_drilldown() + + def __enter__(self): + """Initialises curses for later use.""" + self.screen = curses.initscr() + curses.noecho() + curses.cbreak() + + # The try/catch works around a minor bit of + # over-conscientiousness in the curses module, the error + # return from C start_color() is ignorable. + try: + curses.start_color() + except: + pass + + curses.use_default_colors() + return self + + def __exit__(self, *exception): + """Resets the terminal to its normal state.""" + if self.screen: + self.screen.keypad(0) + curses.echo() + curses.nocbreak() + curses.endwin() + + def update_drilldown(self): + if not self.fields_filter: + if self.drilldown: + self.stats.fields_filter = None else: - stats.fields_filter = r'^[^\(]*$' - update_drilldown() - def refresh(sleeptime): - screen.erase() - screen.addstr(0, 0, 'kvm statistics') - screen.addstr(2, 1, 'Event') - screen.addstr(2, 1 + LABEL_WIDTH + NUMBER_WIDTH - len('Total'), 'Total') - screen.addstr(2, 1 + LABEL_WIDTH + NUMBER_WIDTH + 8 - len('Current'), 'Current') + self.stats.fields_filter = r'^[^\(]*$' + + def refresh(self, sleeptime): + self.screen.erase() + self.screen.addstr(0, 0, 'kvm statistics - summary', curses.A_BOLD) + self.screen.addstr(2, 1, 'Event') + self.screen.addstr(2, 1 + LABEL_WIDTH + NUMBER_WIDTH - + len('Total'), 'Total') + self.screen.addstr(2, 1 + LABEL_WIDTH + NUMBER_WIDTH + 8 - + len('Current'), 'Current') row = 3 - s = stats.get() + stats = self.stats.get() def sortkey(x): - if s[x][1]: - return (-s[x][1], -s[x][0]) + if stats[x][1]: + return (-stats[x][1], -stats[x][0]) else: - return (0, -s[x][0]) - for key in sorted(s.keys(), key=sortkey): - if row >= screen.getmaxyx()[0]: + return (0, -stats[x][0]) + for key in sorted(stats.keys(), key=sortkey): + + if row >= self.screen.getmaxyx()[0]: break - values = s[key] + values = stats[key] if not values[0] and not values[1]: break col = 1 - screen.addstr(row, col, key) + self.screen.addstr(row, col, key) col += LABEL_WIDTH - screen.addstr(row, col, '%10d' % (values[0],)) + self.screen.addstr(row, col, '%10d' % (values[0],)) col += NUMBER_WIDTH if values[1] is not None: - screen.addstr(row, col, '%8d' % (values[1] / sleeptime,)) + self.screen.addstr(row, col, '%8d' % (values[1] / sleeptime,)) row += 1 - screen.refresh() + self.screen.refresh() - sleeptime = 0.25 - while True: - refresh(sleeptime) - curses.halfdelay(int(sleeptime * 10)) - sleeptime = 3 - try: - c = screen.getkey() - if c == 'x': - drilldown = not drilldown - update_drilldown() - if c == 'q': + def show_stats(self): + sleeptime = 0.25 + while True: + self.refresh(sleeptime) + curses.halfdelay(int(sleeptime * 10)) + sleeptime = 3 + try: + char = self.screen.getkey() + if char == 'x': + self.drilldown = not self.drilldown + self.update_drilldown() + if char == 'q': + break + except KeyboardInterrupt: break - except KeyboardInterrupt: - break - except curses.error: - continue + except curses.error: + continue def batch(stats): s = stats.get() @@ -698,7 +730,8 @@ def main(): if options.log: log(stats) elif not options.once: - curses.wrapper(tui, stats) + with Tui(stats) as tui: + tui.show_stats() else: batch(stats) -- 2.3.0